x + y + z = 3 3x + y - 2z = -8 7x - 6y - z = -16 nilai dari x, y, z adalah

x + y + z = 3
3x + y - 2z = -8
____________ _
-2x + 3z = 11

18x + 6y - 12z = -48
7x - 6y - z = -16
_______________ +
25x - 13z = -64

-2x + 3z = 11
25x - 13z = -64

-26x + 39z = 143
75x - 39z = -192
____________ +
49x = -49
x = -1

-2x + 3z = 11
-2(-1) + 3z = 11
2 + 3z = 11
3z = 9
z = 3

x + y + z = 3
-1 + y + 3 = 3
y = 3 + 1 - 3
y = 1

x, y, z = {-1, 1, 3}